B1 - Variation, Reproduction & New Technology Flashcards Preview

GCSE Biology > B1 - Variation, Reproduction & New Technology > Flashcards

Flashcards in B1 - Variation, Reproduction & New Technology Deck (29)
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0
Q

How do parents pass on genetic information to their offspring?

A

They pass on genetic information in the sex cells.

1
Q

What are gametes?

A

Sex cells

2
Q

What are chromosomes?

A

Thread like structure made up of DNA that carry genes.

3
Q

In which part of a cell is the genetic information found?

A

In the nucleus.

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4
Q

What does DNA stand for?

A

Deoxyribonucleic Acid

5
Q

What is the shape of the DNA molecule?

A

A double helix

6
Q

What is a gene?

A

A sequence of nucleic acids in the DNA.

7
Q

How many chromosomes does a normal human have and where from?

A

Humans have 46 chromosomes in 23 pairs. Half from the mother, half from the father.

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8
Q

What is the purpose of a gene?

A

Genes work at the level of the molecules in the body to control the development of characteristics by controlling different enzymes and proteins.

9
Q

Why does asexual reproduction result in genetically identical offspring?

A

There is no joining of gametes and one parent meaning there is no variety.

10
Q

What is a clone?

A

Genetically identical offspring of asexual reproduction.

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11
Q

What types of organisms reproduce asexually?

A
  • Small animals
  • Plants
  • Bacteria
12
Q

How does sexual reproduction produce variety?

A

Male and female gametes join so the mixture of genetic information in the parents leads to variety.

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13
Q

Why is genetic variety important?

A

Variety makes it more likely that the offspring will survive difficult conditions.

14
Q

How are plants cloned?

A

Taking cuttings of mature plants.

15
Q

What can change the characteristics of a person?

A
  • Environment
  • Genetics
  • combination

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16
Q

How is embryo cloning undertaken in cows?

A
  • A top-quality cow is given fertility hormones in order to produce lots of eggs.
  • The eggs are fertilised using the sperm of a decent bull.
  • After growing, the embryo is removed from the womb and divided into several individual cells.
  • The cells grow into identical embryos then are transferred to the host mothers.
  • The mothers have been given pregnancy hormones so then the identical cloned calves are born.
17
Q

How are plants cloned using tissue culture?

A

A mixture of plant hormones is used to make a small group of cells from the desired plant.

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18
Q

Give an advantage of embryo cloning.

A

The cow can produce more calves than by natural means.

19
Q

How is adult cell cloning done?

A
  • The nucleus is removed from an unfertilised egg.
  • The nucleus is also taken from an adult body cell of another animal.
  • The nucleus from the adult cell is transferred into the empty egg cell.
  • A small electric shock causes the egg cell to begin to divide and starts embryo development.
  • The embryo is placed in the womb of a third animal to develop.
  • The animal born is genetically identical to the nucleus donor.
20
Q

Give three disadvantages of adult cell cloning.

A
  • People may abuse the technology to make cloned of themselves.
  • Cloning produces genetically identical organisms, reducing variety. If there is a change in the environment, all of the animals will die because none of them contain the useful characteristic.
21
Q

Give two advantages of adult cell cloning.

A
  • Animals that have been genetically engineered to produce useful proteins in their milk can be cloned.
  • Animals could be saved from extinction or bring back extinct species.

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22
Q

What is genetic engineering?

A

Changing the genetic material of an organism.

23
Q

Explain how insulin is made using genetic engineering.

A
  • Human cells are taken that contain the insulin producing genes.
  • The insulin gene is “cut out” of the DNA using an enzyme.
  • A plasmid is removed from a bacterium and split using an enzyme.
  • The insulin gene is inserted into the plasmid using another enzyme.
  • The plasmid with the insulin gene is taken by the bacterium.
  • The bacterium multiplies many times therefore mass producing insulin.
24
Q

How are genes transferred from one organism to another?

A

Genes from a chromosome are “cut out” using enzymes and inserted to the cells of bacteria and other organisms.

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25
Q

Give six advantages of genetic engineering.

A
  • Specific proteins can be made.
  • Exact amounts can be produced.
  • The protein is very pure.
  • Crops can be adapted making hunger less of an issue.
  • The yield of GM food is generally greater.
  • Plants can produce their own pesticide.
26
Q

Give an example of how animal genes can be transferred interspecies to assist in farming.

A

Glowing genes from a jelly fish have been used to produce crop plants that glow when being attacked by insects.

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28
Q

How can genetic engineering be beneficial for people with genetic diseases?

A

The affected cells can have healthy genes inserted.

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29
Q

Give three disadvantages of genetic engineering.

A
  • Nobody knows the long term effects.
  • GM crops are made infertile meaning farmers have to buy more seed every year.
  • People may want to manipulate the genes of their children.

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